When a vehicle is traveling on snow and/or ice, it is generally desirable to mount chains upon the vehicle's tires to prevent skidding and slipping of the vehicle on the road. The chains will provide improved traction on a road covered with ice or snow. However, on a dry road, chains affixed on a vehicle's tires are unnecessary. Thus, motor vehicle operators must affix chains to their vehicle's tires prior to travelling on snow-covered or icy roads. Once the vehicle has left the snow and ice, the chains must be removed for travel on dry road.
One conventional method of affixing chains to vehicle tires requires the steps of spreading the chain on a road surface, mounting the car tire on one end of the chain by driving the car slowly in a forward or reverse direction upon the chain, raising the opposite end of the chain around the vehicle tire and connecting both ends of the chain. This method has several drawbacks which make it difficult to secure the chain in place around the tire. For example, when the tire comes into contact with the chain, the chain may move in an undesired fashion, making it difficult to securely fasten the chain to the tire.
Another conventional method for affixing chains to vehicle tires involves using a car jack to raise the vehicle tire off the ground, thereby allowing the chain to be wrapped around the raised tire. However, jacking up a vehicle on a wet, snowy or icy surface is dangerous because of the risk that the jack may slip out from under the vehicle and injure a person, or that the vehicle may fall on the person.
Previously, there have been other ramp-type devices which can be utilized to facilitate affixing a chain on a vehicle tire. These other ramp type devices do not have anti-slip features on their underside that comes into contact with the road surface. Furthermore, these other devices to not include a means for preventing the tires from slipping off during affixing of the chain from the vehicle tire or removing the chain from the vehicle tire.
We are aware of the following U.S. patents the disclosures of which are incorporated by reference herein:
U.S. Pat. No. 1,189,632 PA1 U.S. Pat. No. 3,893,500 PA1 U.S. Pat. No. 3,937,263 PA1 U.S. Pat. No. 4,103,870 PA1 U.S. Pat. No. 4,194,724